Relates to:
Mobs
It seems like all Mobs have this Motion when not moving:
Motion:[0:0.0d,1:-0.0784000015258789d,2:0.0d]This might cause problems when testing for an entity based on its Motion value (this won't work currently anyways because of MC-80649).
Minecarts
Another strange this is, that for example Minecarts placed on a rail has this motion:
Motion:[0:0.0d,1:-0.0d,2:0.0d]But it seems like the game makes no difference between 0.0 and -0.0, so this wouldn't be problematic I guess
Linked issues
Comments 5
I think that's @unknown's point. Why have you created two issues about this? The Motion tag doesn't represent the final velocity of an entity, but instead stores the results of the various forces acting on the entity that accelerate it in different directions. Most entities are constantly being subjected to gravity, and thus have a negative Y motion. Minecarts on rails, however, are handled differently, and the normal gravity calculations are disabled for them.
Please do not post two issues if they are really pointing towards the same problem!